Alkali metal silicates are used in a variety of commercial and industrial processes and formulations. However, one commonly encountered problem with their use is that they frequently degrade the surface of equipment used in the process. For example, sodium silicates tend to form a water-insoluble scale on the surface of equipment, especially metal equipment. Especially if allowed to dry, the scale (which may include reaction products with carbon dioxide from the air) is typically insoluble in water and very difficult to remove. The scale can affect moving parts, rollers, etc where a smooth surface is desired for aesthetic or other reasons. Even if removal is successful, there may remain an etched, pitted, or roughened appearance that can create the perception of an unclean surface.
Carbon steel and even stainless steel may be degraded in this way, with degradation taking the form of a buildup of water-insoluble scale or other deposit, or a roughening and loss of gloss of the surface, or other type of deterioration. Other surfaces (for example, plastic and rubber) may also be degraded by contact with alkali metal silicates. Such deterioration may be problematic, particularly since some regulatory agencies require that metal surfaces in certain facilities, for example food handling facilities, be cleaned down to bare metal at the end of each day's operation, thus putting a significant burden on the operators. Therefore, methods and compositions for reducing or eliminating scale formation or other surface degradation of equipment contacted with alkali metal silicates would be of value.